From the FBI
The FBI, Oregon State Police and the U.S. Postal Inspection Service are working with affected Oregon counties to determine the origin and nature of a series of suspicious letters that started arriving in the mail on Monday, July 27th. To date, field testing by hazardous materials crews has shown NO toxic substance on any letter or in any envelope. In addition, at this time there is no evidence of a visible powder to be found in any of the envelopes/letters.
There are approximately 20 known letters delivered and all were addressed to Oregon sheriffs or their offices. Law enforcement is collecting the letters and transporting them all to the FBI and/or the Oregon State Public Health Laboratory for analysis as appropriate.
Due to the on-going nature of this investigation, we are not releasing any further information.